Fifth-grade teacher Dona Ostenso usually enters her Calvert Elementary School classroom by 8 a.m. so she has time to plan lessons and grade papers before her students arrive.

But not since Wednesday. Ostenso said she will not begin her workday until 8:35 a.m. -- the official start time -- unless the Calvert County Board of Education offers the county's teachers a new contract that includes higher wages, more regular breaks and union representation when the instructors face disciplinary action.

"We need a contract!" she and about 40 other teachers and support staff chanted in front of the school at 8:20 Wednesday morning. They clutched signs that read: "Students Count On Us!" and "Honk if You Support Teachers" as passing drivers tooted their car horns.

To express their displeasure over the stalemate in negotiations -- and having to start the school year without an agreement on pay and benefits -- teachers across Calvert County have refused to work more than the 7.5 hours per day required by their contracts. This form of protest is called a "work-to-rule" action. The county teachers union approved the tactic Monday.

The step is an escalation in the contract dispute between the school board and the unions representing teachers and support staff. Union officials hope the protest will win concessions from the board.

But Superintendent J. Kenneth Horsmon said the school board will not be intimidated by the work-to-rule action.

"They are using kids, but it won't work," he said. "The biggest losers here are the students."

Teachers said students would continue to receive first-rate instruction, but they conceded the labor action would have some negative effects.

"We are not going to have parent-teacher conferences after school hours," Ostenso said. "Parents are going to have to take time off from work. That means it is going to be very hard to schedule those meetings."

Some after-school clubs are also affected. The Calvert Elementary recycling club, scheduled to meet before school hours, was postponed indefinitely because a teacher declined to supervise it outside regular working hours, Ostenso said.

Teachers said it will also take them much longer to return papers to students since they will not grade them at home anymore.

Several parents expressed concern that the work-to-rule action would harm their children.

"Our kids are going to get left behind," said Pamela Penar, whose daughter is a fifth-grader at Calvert Elementary. "I'm not agreeable with this."

Ostenso, a single mother who has been teaching in Calvert for 16 years, said it is unfair to criticize teachers for working the schedule specified in the old contract that was extended by school administrators.

"We're not using the children," she said. "We're doing our jobs."